Gaza City -LRB- CNN -RRB- -- Israel 's ground incursion into Gaza , which it says is intended to destroy Palestinian militants ' tunnels and stop rocket fire into Gaza , has entered its fifth day with the death toll mounting on both sides and U.S. Secretary of State John Kerry arriving in Egypt . CNN 's Ben Wedeman , a veteran Middle East correspondent , puts the incursion into perspective .

How does this incursion compare to previous ones by Israel into Gaza , in terms of military force ?

Unlike 2008/09 , this incursion seems to be focused on areas with high concentrations of people , initially focusing on the Gaza City neighborhood of Shaja'ia . In ' 08/09 the focus was on areas where rockets were being fired , which were typically away from highly populated communities .

And of course at this stage , it 's unclear how many Palestinian casualties there have been in these locations . The people have been warned by the Israelis to leave these areas with phone messages , but while many have left , a significant proportion has stayed behind .

My impression is that Israel has mobilized a much larger military force than in 2008/09 and in 2012 . This is part of the picture of the Israelis going into heavily populated areas -- which is a much more dangerous operation , as can be seen by the deaths of at least 13 Israeli soldiers on Sunday .

Is Israel likely to achieve its objective of destroying the tunnels , and stopping the rocket strikes ?

So far , Israel has n't been wildly successful in its stated mission . Since this started , Hamas has been using tunnels in an attempt to ambush and capture soldiers and continues to fire rockets at Israel , although the number fired has gone down . What we see is that as Israel 's capabilities have changed , so have Hamas ' . Whenever Israel comes up with new tactics , Hamas and other factions seem to find new ways to counter them , such as by using longer-range rockets to fire at Israel , for example .

What is significant now is that Hamas fighters appear to be better trained , with a new set of skills that I do n't think Israel anticipated . One Israeli soldier who came out of Shaja'ia was quoted in an Israeli publication that Hamas is fighting like Hezbollah , which waged a successful guerrilla war against Israel 's occupation in the 1980s and 1990s , and inflicted high casualties on Israeli forces during the 2006 war between Hezbollah and Israel in Lebanon .

The last serious street fighting I saw in Gaza was in early 2008 , and it was almost like it was `` amateur hour , '' with fighters in Gaza parading around with their weapons but not really able to stop the Israeli forces . Now it appears they 've learned they must keep a much lower profile . They 've developed what could be called commando tactics , and are taking full advantage of their knowledge of their turf .

How long do you believe this incursion will last ? How soon before it realistically is better described as a war ?

This is now a war , in my modest opinion -- it 's gone beyond a mere incursion . Hamas shows no sign of backing down , and did n't jump at Egypt 's cease-fire proposal . They want to show that they 're a military force to be reckoned with , and are in it for the long run .

Israel 's defense minister said it would take two or three days to destroy the tunnels . If this crisis is to end soon , Israel will have to pull back and Hamas needs to stop firing rockets . In Hamas ' opinion , they have achieved one of their objectives , which is to give Israel a bloody nose .

They claim to have captured an Israeli soldier -- as yet this is unconfirmed -- but if true , it would be a huge feather in their cap , in their own terms . When Israeli soldier Gilad Shalit was captured by Hamas in a June 2006 raid near the Israel-Gaza border , it took five years before he was freed , in exchange for more than 1,000 Palestinian prisoners -- so , if true , this will be a huge bargaining chip for Hamas .

Will the death toll already suffered by Israel have a serious impact on public opinion in Israel ?

Israelis are used to this sort of death toll from Hezbollah , but not from Hamas . I was on the streets of Gaza on Sunday night , when Palestinians celebrated the claims that an Israeli soldier had been captured .

Shortly afterwards , the guns on Israeli navy boats opened up . The immediate conclusion of everyone in the street was that this was Israel 's response to the capture of one of its soldiers .

How much effect will the pressure/condemnation from the United Nations -LRB- and in the off-mic remarks from U.S. Secretary of State John Kerry -RRB- have ?

I believe the U.N. remarks will have no effect in Gaza . There is a perception there that the U.N. `` talks but does n't walk '' -- it 's toothless in other words . Hamas realizes it has few friends in the outside world .

The remarks of the White House last week though will not go down well in Israel , I believe . And the comments of John Kerry on Sunday -- which left some wondering whether he was criticizing Israeli assurances that its ground offensive in Gaza would be limited -- indicate American patience may be wearing thin . After one of his deputies mentioned the latest number of Palestinian casualties , Kerry was heard to say , `` It 's a hell of a pinpoint operation . ''

It is estimated that 70 % of the more than 500 Palestinians killed in Israel 's assault have been civilians . Washington has tied itself to Israel , and that country 's right to self-defense , therefore the U.S. is going to feel some responsibility . Americans support Israel rhetorically , but this high Palestinian death toll is very problematic for the U.S. . This is why Kerry may be feeling uncomfortable -- he spent almost a year trying to forge a Mideast peace deal , and what 's he got to show for it now ?

Kerry seeks Gaza cease-fire amid rising casualties

Peter Wilkinson in London contributed to this report .

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CNN 's Ben Wedeman says Hamas is a stronger force this time

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It has adopted commando-like tactics , he says

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There was cheering at reports of an Israeli solider captured

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U.S. has little to show for a year of trying to forge peace , he says